Using fish assemblages in different habitats to develop a management plan for the Upper Essequibo Conservation Concession, Guyana

ABSTRACT

The Upper Essequibo Conservation Concession is a reserve in central-eastern Guyana managed by Conservation International. The site is uninhabited by people and poorly studied. The first scientific fish survey was in 2007 in conjunction with the filming of the BBC nature documentary Lost Land of the Jaguar. Aquatic habitats were primarily flowing water, ranging from the main channel of the Essequibo River to small forest creeks. Ponds and seasonally flooded forests were uncommon. Large predatory fishes were abundant in the Essequibo River. Fishes tolerant of low oxygen levels were common in flooded forests and small forest creeks. There was zero similarity between the fish assemblages of the Essequibo River and flooded forests / small forest creeks. The rest of the habitats and fish assemblages formed a continuum between these extremes. Imminent threats to the Upper Essequibo Conservation Concession include logging, mining, and over-fishing. Because of the heterogeneous distribution of fish assemblages, and because each threat will differentially affect different habitats, a two-pronged approach focusing on the ends of the habitat / fish assemblage continuum should be implemented in order to conserve the entire fish biodiversity of the Upper Essequibo Conservation Concession.

RESUMO

La Upper Essequibo Conservation Concession es una reserva en Guyana centro-oriental, administrada por Conservation International. El sitio está deshabitada por personas y mal estudiado. El primer estudio científico de peces fue en 2007 junto con la filmación del BBC documental naturaleza Lost Land of the Jaguar. Hábitats acuáticos fueron el canal principal del Río Essequibo a quebradas pequeñas del bosque. Lagos pequeños y bosques inundados estacionalmente eran infrecuentes. Grandes peces depredadores abundaban en el Río Essequibo. Peces tolerantes con bajos niveles de oxígeno eran comunes en quebradas pequeñas del bosque y bosques inundados. Hubo cero similitud entre las comunidades de peces del Río Essequibo y bosques inundados / quebradas pequeñas del bosque. El resto de los hábitats y comunidades de peces forma un continuum entre estos extremos. Las amenazas inminentes a la Upper Essequibo Conservation Concession incluyen deforestación, la minería y sobrepesca. Debido a la distribución heterogénea de comunidades de peces y porque cada amenaza diferencialmente afectarán a diferentes hábitats, un enfoque doble centrándose en los extremos del hábitat / comunidades de peces continuum debe aplicarse con el fin de conservar la biodiversidad de peces entero de la Upper Essequibo Conservation Concession.